Production of blanks for tamperproof seals



April 30, 1940. s, PEmcE 2,199,113

PRODUCTION OF BLANKS FOR TAMPERPROOF SEALS Original Filed March 13, 1935 f'zvenz Zr/ Patented Apr. 30, 1940 PRODUCTION} OF BLANKS FOR TAMPER- PROOF SEALS Ralph s. Peirce, ,Hinsdale, n1.

Original application March 13, 1935, Serial No.

10,775, now Patent No. 2,108,942, dated Febrm I ary '22, 1938. Divided and this application -February12, 1938, Serial No. 190,287

Claims. (01. 29-148) This invention relates .to the production of blanks for tamperproof seals.

Particularly on gas and electric service meters, for example, which are intended to be sealed .5 against unlawful access, it is important that the seals not only be such that the y.cannot be removed and replaced without being broken; but also that unauthorized or so-called bootleg seals be not substituted for the original seal after the first has been destroyed and unauthorized access had to the meter.

Among other objects, my invention aims to provide an improved blank for such a seal and method of producing the same which meets both of these requirements and which can be produced in large quantities at extremely small individual cost. The seal itself and method of producing its final form are covered by my Patent No. 2,108,942 of February 22, 1938, of which the present application is a division.

' Th invention will be understood byreference to the accompanying drawing illustrating one form of seal blank made in accordance with the method of my invention.

Inthe drawing,

Figure 1 is a fragmentary view 'offsimple but practicalexpedients, parts being shown in section, for practicing a preferred early step in my invention, the expedients being shown in separated relation prior to the performance of the step;

Figure 2 shows a view of the expedients of Fig. 1 in cooperative relationship, other parts being shown in section;

Figure 3 is a similar view, partly in section, but subsequent to the performance of a succeeding step;

Figure 4 shows the results of the performance of the steps indicated by the previous figures;

Figure 5 shows the introduction of a malleable member, of the seal, shown in section, and one means, also shown'in section, for forming the malleable member in accordance with the invention; I

Figure 6 shows a preferred operation on the malleable member in accordance with my invention;

Figure '7 shows a, completed seal blank made by the performance-of the steps indicated by the Figure 3 is a OIOSS-section taken on the line 5 1-! 015 s. 9 e lsrsg sw i and previous figures, the malleable member of the Figure 9 is a cross-section taken on the line 9-'-9 of Fig. 2 on a larger scale.

Referring in detail to the figures of the drawing, I have shown a pin-like mandrel Iii" having an enlarged shank H by which the mandrel is supported by any suitable-holder l2, having, in this instance,'a bore l3 rotatively receiving the cylindrical shank ll of the mandrel with the shoulder l4 between the shank and the mandrel proper and the, mandrel itself, projected from the holder l2. The shank H maybe suitably keyed (not shown) to the holder l2 to prevent axial but permit J the 'rotative movement under the influence of, for example, a belt (also not shown) running on the pulley wheel i la integral with the shank. As best shown in Figs. 1 and 8,

- the'shank H of the mandrel is provided with a longitudinally extending slot 15 through which a flexible element for my improved seal, represented in this instance by the wire 16, is passed. The wire [6 may be of the stranded or braided type or may be solid .v This slot I5 also passes through the. pulley wheell la. The wire It may be cut ofi, by any suitable means not here shown,

to appropriate length for purposes of the seal and one end ll of the wire maybe pushed or pulled through the slot l5 to lie along side of and initially parallel with the mandrel l0. It will be understood that the expedients just described are merely one illustrative means of holding the wire and mandrel in-this initial relationship, andthat substantially the same result could be accomplished by hand.

First maintaining the wire and mandrel in the described initial relationship, I next proceed to loopthe end I! of the wire about the mandrel.

' While this might be accomplished by'hand, I have illustrated one practical expedient or aid-t0 accomplish this next step in the process, here represented by the sleeve l8 and the relative move- ,ment provided for between the shank II and the sleeve. Thesleeve I8 may be suitably retracted in the holder I9; As here shown, the

, sleeve I8 is recessed or bored as at 20 cylindrically to snugly receive the mandrel I0 which is also desirably cylindrical. To receive the wire also when the mandrel and wire are associated as shown, the bore 20 of thesleeve I8 is enlarged radially and axially as at 2| and as best shown in Figs. 2 and 9. Thus, by slipping the sleeve l8 over the wire and mandrel with the wire located in the slot 2|, and then rotating the mandrel while holding the sleeve l8 against rotation, the

end'l'l of the wirewill be caused to loop about the mandrelas indicated inFig. 3. As will be seen, the wire lies longitudinally along the mandrel, one end of the wire being held against rotative movement about the axis of the mandrel while the other end is caused to rotate about said axis. To assist in locating the wire in the slot 2| I may advantageously project the extreme end of the wire slightly beyond the mandrel as shown in Figs. 1 and 2. Furthermore, by withdrawing the sleeve from the mandrel during the rotation of the mandrel I may dispose the end of the Wire in a plurality of helical turns 22 Where looped about the mandrel.

After withdrawing the sleeve l8, as shown in Fig. 4, I next proceed to associate the sealing member of my improved seal with the flexible member or wire, this sealing member being here represented by the cylindricalv slug 23 desirably composed of a malleable or relatively soft metal such as lead. As shown in Fig. 5, I slip the slug 23 over the mandrel and turns 22 of the wire, the shoulder M on the mandrel assisting in locating the slug over the turns of the wire, this shoulder having of course previously assisted in forming the first turn of the wire relatively close to the shoulder l4. With the mandrel, wire and slug held in this relationship, I next proceed to form the slug about the wire and mandrel. While this might be done by hand, I advantageously provide compressing expedients such as the complementary jaws 24, 25 between which the mandrel, wire and slug are inserted and which are relatively movable with respect to the mandrel as shown in Figs. 5 and 6, so as to compress the slug 23 transversely while permitting it to expand longitudinally.

The jaws 24, 25 are desirably somewhat maleand-female, the upper or male jaw 24 being recessed semi-cylindrically as at 26 to form a semi-cylindrical portion of the lead as shown in my said patent, the lower or female jaw 25 has the more generally rectilinear recess 28 forming the somewhat flattened portion 30 of the lead. Upon compression of the lead as just described, with the mandrel and wire remaining in the relationship shown, the mandrel main tains the helical disposition of the wire while at the same time causing the wire to be imbedded in the lead, which is forced by the jaws between the turns of the wire and into contact with the mandrel except where the wire intervenes as best shown in Fig, 6. Thus when the mandrel is withdrawn, as shown in Fig. 7, the next step in my process, a bore 3| is left in the lead, with the turns 22 of the wire looped about the walls of the bore 3| and securely anchored in the lead, with the opposite end 32 of the wire I6 initially free, so that the wire may be bent upon itself and the end 32 freely moved through the bore 3! of the lead.

At some stage in the formation of the sealing member subsequent to its intermediate stage as indicated by the numeral 33, in accordance with another aspect of my invention, I provide the intermediate sealing member 33 with any identifying mark or marks desirably in the nature of a figure formed by a groove or grooves depressed below the normal surface of the lead. Such a figure is here represented by the concentric circular grooves 34 formed in the flat surface 30 of the lead when in its intermediate state 33. This figure may be readily formed during the compression step shown in Fig. 6 by providing one of the jaws, as here shown the female jaw 25, with embossments 35 in the shape of two concentric circles, these embossments, after com.-

pression of the parts, leaving the concentric grooves 34 in the lead, for the purpose disclosed and claimed in my said patent.

It will be understood that the intermediate sealing member 33 might be formed as just described from a solid but plastic or malleable slug 23, or might even be formed by casting (in a molten state) the lead or the like initially about the associated mandrel and wire shown in the step of Fig. 4.

When used the seal blank shown in Fig. 7 is compressed by the usual sealing tool (not shown) transversely to the bore 3| and causing the free end 32 of the wire to contactually intersect with the turns 22 and thus lock the free end. At that time the configuration 34 is altered as described and claimed in my said patent.

When the wire I6 is of the stranded type, in accordance with one aspect of my invention, the individual strands of the finally twisted stranded wire l6 may be assembled separately in a guide plate I00 having the three spaced apart holes ml, 12 and I03, if, for example, there be three strands for the final wire. The individual strands Ilia, 16b and I60 may then be together pushed or pulled through the slot l5, and thereupon the rotation of the mandrel l0 and shaft I! will twist the individual strands lEa, Ifiband 160 into the unitary twisted stranded wire l6 and at the same time wind the end 22 of this wire about the mandrel. It will be understood that after the slug 23 has been made a part of the seal blank in association with the wire as shown in Fig. 6, the jaws 24 and 25 may then be employed to hold the slug 23 and with it the end of the wire [6 which is secured to the slug, while by suitable means, not here shown, the holder [2 and with it the shank l I and mandrel l 6 may be retracted toward the left-hand side as shown in the drawing on the wire 16, and suitable means (not shown) may then be employed to sever the wire desirably at a point to the right-hand side of the mandrel I 0, leaving a portion of the already twisted strands [6a, I61) and I60 within the slot l 5 and preferably projecting in the righthand direction slightly beyond the end of the mandrel l0. Thereupon the holder l2 and with it the mandrel is again advanced toward the right-hand side as shown'in the drawing, the friction between the wire in the slot 15 and other parts being sufiicient to drag the wire forward with the mandrel and thus ready for another cycle of operation as already described, beginning with Fig. 1, for the production of another seal blank, as shown in Fig. '7.

It will be understood that there is sufficient space in practice between the guide plate Hill and the pulley Ha to permit a considerable length of the wires to be twisted into the twisted stranded wire l6 by rotation of the mandrel. It may happen that when the mandrel is initially threaded with the three separate strands untwisted, the rotation of the mandrel the first time will not twist the wires into the twisted stranded wire throughout its entire length with: in the slot l5, but this first or leading length of wire if not sufiioiently twisted may be discarded, and thereafter all succeeding lengths of the wire will be formed intothe twisted stranded wire I6 as described.

Obviously, the invention is not limited to the details of form and sequence of steps of operation described above for purposes of illustration.

Such changes may be made as fall within the scope of the following claims, as limited by the prior art, without departing from the invention. Furthermore, it is not essential that all features of the invention be used conjointly, as various combinations and sub-combinations might be advantageously employed.

Having described my invention, I claim:

1. The method of producing tamperproof seal blanks or the like which is characterized by the steps of laying a flexible wire-like member longitudinally along a mandrel, holding one end of the member against rotative movement about the axis of the mandrel while causing the other end of the member to rotate about said axis to loop the member about the mandrel, forming a soft metal member about the mandrel and looped member with the member embedded in the soft metal member, and withdrawing the mandrel.

2'. The method of producing tamperproof seal blanks or the like which is characterized by the steps of laying a wire longitudinally along a mandrel, holding one end of the wire for rotative movement with the mandrel about the axis of the mandrel while holding the other end of the wire against rotation about said axis, rotating the mandrel to loop the wire about the mandrel, compressing a soft metal member over the mandrel and looped wire with the wire embedded in the soft metal member, and withdrawing the mandrel.

3. The method of producing tamperproof seal blanks or the like which is characterized by the steps of laying one end of a wire longitudinally along a mandrel, holding one end of the wire against rotative movement about the axis of the mandrel while causing the other end of the wire to rotate about said axis to loop the wire about the mandrel, drawing the wire where so looped along th mandrel so as to cause the loop to describe a'helix, forming a soft metal member about the mandrel and looped wire with the wire embedded in the soft metal member, and withdrawing the mandrel.

4. The method of producing tamperproof seal blanks or the like, which is characterized by the steps of laying strands of wire along a rotatable mandrel, rotating the mandrel both to twist the strands together and to loop the jointly twisted strands about the mandrel, compressing a soft metal member over the mandrel and looped wire, retracting the mandrel on the wire while holding the soft metal member and wire, and severing the wire while leaving an end thereof on the mandrel.

5. The method of producing tamperproof seal blanks which is characterized by the steps of advancing an uncoiled end of a continuous wire of sufiicient length to produce a plurality of said blanks into position to be rotated about the mandrel, coiling said end about said mandrel, forming a soft metal member about the mandrel and coiled end with the said end embedded in the soft metal member, severing the wire adjacent said coiled end, and subsequent to said forming withdrawing the mandrel.

RALPH S. PEIR'CE. 

